TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4248 SUBJECT: GRB051111: Swift-BAT detection of a bright burst DATE: 05/11/11 06:38:44 GMT FROM: David Palmer at LANL T. Sakamoto (GSFC), D. Burrows (PSU), S. Immler (GSFC/USRA), N. Gehrels (GSFC), S. Hunsberger (PSU), F. Marshall (GSFC), D. Palmer (LANL), V. La Parola (INAF-IASFPa) on behalf of the Swift team: At 05:59:41 UT, Swift-BAT triggered and located GRB051111 (trigger=163438). The BAT on-board calculated location is RA,Dec=348.157,+18.367 {23h 12m 38s,+18d 22' 03"} (J2000), with an uncertainty of 3 arcmin (radius, 90% containment, stat+sys). The BAT light curve showed a broad single peak with a 10 second rise to a peak of 4000 counts/s (15-350 keV) around T+0 with decaying emission at least to T+20. The spacecraft did not automatically slew due to Moon constraint. A ToO observation is being planned.